Internal-combustion engine



March 25, 1911?. R. D. BRUEGGR 2,417,910

INTERNAL COMBUSTION ENGINE l Filed'June 2o, 1942 2 sheets-sheet 1 March 25, 1947. R D BRUE-GGER 2,417,90

INTERNAL COMBUSTION ENGINE Filed June 20, 1942 2 Sheets-Sheet 2 Patented Mar. 25, 1947 sie This invention relates to an internal combustion engine, and more particularly to an engine equipped with an improved mechanism for transmitting power from the pistons to the crank shaft or crank shafts.

An object of the invention is to provide in an internal combustion engine, increased power with conventional piston and cylinder construction. Another object is to pro-vide a longer stroke for the piston in an internal combustion engine with- -out increasing the displacement in the crank shaft. Still another object is to provide mechanism for increasing the portion of the are of the crank shaft in which the piston is under power, and at thesame time to decrease the portion of the arc of the crank shaft in which the piston accomplishes the return stroke. A further object is to provide for the more rapid expulsion of exhaust gases in an internal combustion engine by providing in combination with a crank shaft which rotates at a uniform speed, a piston which moves more rapidly on the upward .stroke than on the downward stroke.

Another object of the invention is to provide a mechanism in an internal combustion engine for transmitting power from the pistons to the crank shafts and at the same time avoiding any tendency of the piston to move laterally within the cylinder. Still another object is to provide a dual crank shaft construction wherein the tendcncy toward lateral thrust of the piston rod and the piston secured thereto is balanced. A further object is to reduce cylinder wear and to make feasible the use of valves of the sleeve type in an internal combustion engine by reason of the elimination of side thrust in the pist-on.

Other features and advantages will appear from the following specification and drawings, in which- Fig. 1 is a vertical sectional view of the improved engine showing a single piston and the dual crank shaft construction; and Fig. 2 is a similar vertical sectional view of a modied form oi the invention.

The invention contemplates a dual crank shaft construction wherein the pistons are equipped with depending piston rods which are pivotally secured to laterally-extending connecting rods secured to the crank shafts. The dual crank shafts are disposed on opposite sides of the piston in order to balance any tendency for lateral thrust of the piston within cylinder. The linkage between the piston and the crank shafts is so constructed that the down 'stroke 0r power stroke of the piston encompasses a large portion of the arc of the crank shafts while the upward stroke of the piston encompasses a smaller portion of the arc.

In the embodiment of the invention described herein and referring particularly to Fig. 1, the internal combustion engine may be equipped with a conventional cylinder block l@ and a cylinder head l i. The cylinder block lil includes a jacket i2 fo-r water or other cooling medium and provides a cylinder wall i3 within which maybe received a valve l of the sleeve type.

The sleeve valve iii may be cf the conventional construction well known in the 'art and will not be described in detail herein. The valve may include a pair of cylindrical sleeves i5 and It, one disposed within the other within the cylinder wall. The sleeve i5 may be equipped with apertures Il and i8, while the inner sleeve It may be provided with apertures i@ and 2c. Connecting rods 2l and 22 mounted on crank arms of suitable crank shafts are connected to the sleeves l5 and I6 respectively and are adapted to reciprocate the sleeves vertically within the cylinder i3. When the piston 23 in the cylinder i3 is at the upper portion of its exhaust stroke, the openings Il and 253 are adapted to be brought into register so as to bring the inlet port 2t into communication with the chamber 25 at the upper portion of the cylinder. Similarly, when the piston 23 is at the lower portion oi its power stroke, the openings I8 and i9 are adapted to be brought into register to permit communication between the exhaust port 2t and the chamber 25 at the upper portion of the cylinder.

The cylinder head il may be of conventional construction and is mounted on the block I0, the gasket 2l serving to seal the junction. A spark plug 28 is received within the head and extends into the chamber 25 at the upper portion of the cylinder.

`The piston 23 may also be of conventional construction and is provided with piston rings 29 and with a wrist pin 3G, to Iwhich the elongated piston rod Si is pivotally attached.

To the cylinder block lli may be secured the crank case 32, which in turn receives the crank case pan 33, in accordance with conventional construction. A pair of crank shafts Si and 35 are disposed on opposite sides of the piston rod 3| and may be supported by suitable bearings (not shown) of the conventional type. The crank shafts 3d and 35 are equipped with crank arms 35 and 3l respectively and counterbalances 38 and 39 opposite the crank arms. Bearings ill and 4| or" conventional construction pivotally support the connecting rods 42 and 43, which at their opposite ends are pivotally mounted at 44 and 45 respectively on the lower end of the piston rod 3l. The connecting rods 42 and 43 should be of such length that when the piston 23 is at the top of its stroke, as shown in full lines in Fig. 1, the crank arms 36 and 31 are disposed at a relatively small angle above the horizontal on the outside portion of the cycle of each. As shown, this angle is in the neighborhood of 25. Preferably, the angle is between and 65 with respect to the horizontal.

The crank shafts 34 and 35 are equipped respectively with gears 46 and 41. A large gear 48 of the internal-external type is arranged to mesh with the gears 46 and 41, the internal gear 49 meshing with the gear 46, and the external gear 50 meshing with the gear 41. The large gear 48 is mounted on a shaft 5I, which may be used as a power takeoff for the engine.

In the embodiment of the invention shown in Fig. 2, the engine is equipped with poppet type valves, and the dual crank shafts are provided with gears which mesh directly with each other to synchronize the movement of the crank shafts. In this construction, the cylinder block 52 is provided with a jacket 53 for water or other cooling liquid, and forms a cylinder 54 receiving the conventional piston 55. The cylinder head 55 is also of conventional construction'and receives a spark plug 41 and valves 58 of the conventional type. The valves are operated by a cam shaft 59 in accordance with the usual practice in internal combustion engines.

The crank ease 6D and crank case pan 6| include the dual crank shafts 62 and 53. The connecting rod and piston arm construction are the same as that shown in Fig. l and need not be again Vdescribed in detail.

The crank shafts 62 and 63 are equipped with gears 64 and 65 which are arranged to mesh with each other to synchronize the movement of the crank shafts. A suitable housing 66 may be provided at one end of the crank case for enclosing the large gears 64 and 65. By reason of the meshing of the gears 64 and 65 to synchronize the movements of the crank shafts 62 and 63, the power takeoff from the engine may be made at either of the crank shafts 62 or 63.

In the construction shown in Fig. 2, the piston rod 61 may be considerably shorter than the piston rod 3|, shown in Fig. l, since no space accommodations need be made within the crank case for the sleeve valves. In other respects, the piston rod 61 corresponds to the piston rod 3i.

Operation In the operation of the embodiment of the invention shown in Fig. 1, the gasoline or fuel is introduced through the inlet port 24 and through the apertures l1 and 20 in the sleeve valve i4 into the chamber 25 at the top of the cylinder I3. The apertures I1 and 20 are brought into alignment when the piston is at the top of its stroke so that as the piston is drawn downwardly within the cylinder I3, the fuel is drawn into the cylinder. When the piston reaches the bottom of its stroke, the sleeves l5 and I5 are shifted to the position shown in Fig. 1 wherein the apertures l1 and 20 are out of alignment. The piston is then moved to the upper portion of the cylinder, compressing the fuel within the chamber 25 at the upper portion of the cylinder. The firing of the spark plug causes the fuel to be fired, and the piston is forced downwardly Within the reaches the bottom of its stroke, the valves l5 and I6 are shifted so that the apertures i8 and i9 are brought into alignment and bring the chamber 25 into communication with the eX- haust port 26. As the piston rises to the upper portion of the cylinder, the exhaust gases are forced out of the cylinder through the exhaust port 26.

When the piston is at the top of its stroke, the connecting rods and crank arms are in the position shown in full lines in Fig. 1. As the piston moves downwardly on its power stroke, the piston rod 3l moves downwardly and carries with it the connecting rods 42 and 43, which in turn draw the crank arms 36 and 31 of the crank shafts 34 and 35 about an arc until the position shown in dotted lines in Fig. 1 is reached at the bottom of the piston stroke. It will be noted that during the downward stroke of the piston, the crank arms travel through an arc of approximately 217. l

After the piston reaches the bottom of its stroke, the crank shaft 34 continues to rotate in a clockwise position, while the crank shaft 35 continues to rotate in a counter-clockwise position. This rotation brings the crank arms back to the original position shown in full lines in Fig.

cylinder on its power stroke. When the piston 1. During this movement, the crank arms travel through an arc of approximately 143.

Since the crank shafts rotate at uniform speed, the upward movement of the piston which is encompassed by asmaller arc in the rotation of the crank shaft must be carried out more rapidly than the downward stroke of the piston. Accordingly, the exhaust gases in the cylinder at the end of the power stroke 0f the piston are removed more rapidly than is possible in the conventional internal combustion engine.

The movement of the crank arms of the crank shafts through a large portion of the arc of the same during the down stroke of the piston means that on the power stroke of the piston, a greater portion of the arc of movement of the crank arms is encompassed, and accordingly greater power will be obtained from this power stroke. At the same time, a longer piston stroke is possible for a given crank arm radius than would be possible with the conventional type of linkage.

The length of arc through which the crank arm may pass on the down stroke of the piston may be varied as desired. The crank arm, however, is preferably disposed at a substantial angle of at least 10 or 20 above the horizontal when the piston is at the top of its stroke in order that a dead center position which might lock the piston at the top of its stroke will not be reached. If desired, the portion of the arc through which the crank arm passes on the down stroke of the piston may be decreased by arranging the crank arms at a greater angle than shown with respect to the horizontal when the piston is at' the top of its stroke. However, it is preferable to use as great an arc as possible for the down l stroke of the piston without approaching the dead center position which is reached when the crank arm is in horizontal position when the piston is at the top of its stroke. In varying the position of the crank arm when the piston is at the top of its stroke, the length of the connecting rod which joins the crank arm and the piston rod must, of course, be suitably varied.

The crank shafts 34 and 35 are preferably disposed above the lower end of the piston rod, even when the piston rod is in upper position as shown in full lines in Fig. 1. If theI crank shafts 34 and 35 are placed below the piston rod 3l and on opposite sides thereof, the linkage between the crank arms and the piston must of necessity be of much greater length and would ordinarily require'additional support. Preferably, the crank shafts are placed as close to the piston rod 3l as possible so that the angle formed between the connecting rod and the piston rod is as small as possible. As shown, when the piston is at the bottom of its stroke, the angle formed between the connecting rod and the piston rod is approximately 21. As the crank shafts are moved away from the piston rod 3l and the angle between the connecting rods and the piston rod is increased, the effectiveness of the drive connection is decreased.

Although the engine has been described in connection with a vertical cylinder having crank shafts below the same and above the lower ends of the piston rod, the entire engine may, if de sired, be turned at an angle and may be arranged with the longitudinal axis of the cylinder in the horizontal plane. Accordingly, in referring to the various parts and elements of the structure as above or below or to either side of other elements, a structure in which the engine is disposed in a different plane is, of course, intended to be included, and such reference is used only in connection with the relative location of the various parts and elements of the engine.

By reason of the disposition of the dual crank shafts on opposite sides of the pist-on rod 3l and the symmetrical linkages provided between the crank shafts and the piston rod 3i, the crank shafts serve to balance each other with respect to lateral thrust on the piston rod 3l and piston 23 carried thereby. Accordingly, substantially all lateral or side thrust of the piston 23 within the cylinder I3 is eliminated. This makes it feasible to use sleeve valves within the cylinder without dimculty as to wear on the valves as a result of side thrust of the piston.

The internal-external gear 48 serves to synchronize the movement of the crank shafts S4 and 35 and provides on the shaft 5| a power takeoff for the engine.

The operation of the embodiment shown in Fig. 2 is substantially the same as that shown in Fig. 1 except that the poppet valves 58 of the conventional type are used for introducing the fuel into the cylinder and for withdrawing the exhaust gases therefrom. The gears 66 and S5, which are arranged to mesh with each other, synchronize the movement of the crank shafts 62 and 63. Either of the crank shafts 62 or 63 may be used as the power takeoff for the engine.

Although the invention has been described in connection with certain specific embodiments, it will be understood that changes and modiications may be made without departing from the spirit and scope of the invention.

I claim:

1. In an internal combustion engine, a piston, a piston rod depending therefrom, a pair of crank shafts symmetrically disposed on opposite sides of the piston rod, a pair of connecting rods pivotally connecting said crank shafts with the lower end of said piston rod, the connecting rods being symmetrically disposed on opposite sides of the piston rod whereby lateral thrust on the piston rod is balanced, and gear means carried by each of said crank shafts, and an internalexternal gear arranged to mesh with said gear means to synchronize the rotation of said crank shafts.

2. In an internal combustion engine, a piston mounted for reciprocation within a cylinder, a piston rod depending from the piston and extending from the cylinder, a pair of rotatable crank shafts symmetrically disposed on opposite sides of said piston rod and above the lower portionv of the same, a crank arm carried by each of said crank shafts, each of the crank arms being disposed at an angle between 10 and 60 with respect to the horizontal when the piston is at the upper end of its stroke, a connecting rod pivotally secured at one end to each of said crank arms and extending downwardly therefrom to a portion of the piston rod below the crank shafts, means for pivotally securing each connecting rod to the piston rod, gear means carried by each of said crank shafts, and an internal-external gear arranged to mesh with said gear means to synchronize the rotation of said crank shafts.

ROBERT D. BRUEGGER.

REFERENCES CITED The following references are of record in the le of this patent:

I UNITED STATES PATENTS Number 

